Variable volume plasma processing chamber and associated methods

Abstract

A plasma processing chamber includes a substrate support having a top surface defined to support a substrate in a substantially horizontal orientation within the chamber. The plasma processing chamber also includes a number of telescopic members disposed within the chamber outside a periphery of the substrate support. The number of telescopic members are also disposed in a concentric manner with regard to a center of the top surface of the substrate support. Each of the number of telescopic members is defined to be independently moved in a substantially vertical direction so as to enable adjustment of an open volume above the top surface of the substrate support, and thereby enable adjustment of a plasma condition within the open volume above the top surface of the substrate support.

1. A plasma processing chamber, comprising:
 a substrate support having a top surface defined to support a substrate in a substantially horizontal orientation within the chamber; and 
 a plurality of telescopic members disposed within the chamber outside a periphery of the substrate support and concentric with both a center of the top surface of the substrate support and with each other, wherein each of the plurality of telescopic members is defined radially adjacent to its neighboring ones of the plurality of telescopic members such that a radial gap is not present between any neighboring ones of the plurality of telescopic members, wherein each of the plurality of telescopic members is defined to be independently moved in a substantially vertical direction relative to the top surface of the substrate support so as to enable adjustment of an open volume above the top surface of the substrate support, and wherein each of the plurality of telescopic members is structurally defined such that the plurality of telescopic members form a contiguous telescopic member arrangement at all vertical positions of the plurality of telescopic members. 
 
     
     
       2. A plasma processing chamber as recited in  claim 1 , wherein the plurality of telescopic members are defined as concentric cylinders. 
     
     
       3. A plasma processing chamber as recited in  claim 1 , wherein the plurality of telescopic members is three telescopic members. 
     
     
       4. A plasma processing chamber as recited in  claim 1 , wherein each of the plurality of telescopic members is defined to have a different radial thickness such that the radial thickness of the plurality of telescopic members increases with increased radial position relative to the substrate support. 
     
     
       5. A plasma processing chamber as recited in  claim 1 , wherein a telescopic member having a radial position closest to the substrate support includes an inner surface profile defined to optimize a radiofrequency power coupling uniformity and gas flow dynamics within the chamber. 
     
     
       6. A plasma processing chamber as recited in  claim 1 , wherein each of the plurality of telescopic members is formed from an electrically conductive material and is electrically connected to a ground potential. 
     
     
       7. A plasma processing chamber as recited in  claim 1 , wherein each of the number of telescopic members is formed from a dielectric material. 
     
     
       8. A plasma processing chamber as recited in  claim 1 , wherein at least one of the number of telescopic members is formed from a dielectric material and at least one of the number of telescopic members is formed from an electrically conductive material connected to a ground potential. 
     
     
       9. A plasma processing chamber as recited in  claim 1 , wherein a home position of the plurality of telescopic members is defined within an upper region of the chamber, each of the plurality of telescopic members defined to be independently moved downward from the home position so as to enable adjustment of the open volume above the top surface of the substrate support. 
     
     
       10. A plasma processing chamber as recited in  claim 9 , further comprising:
 a stepper motor mechanically connected to move each of the plurality of telescopic members, wherein the stepper motor is defined to limit movement of each of the plurality of telescopic members from the home position to a position of its immediately surrounding telescopic member. 
 
     
     
       11. A plasma processing chamber as recited in  claim 1 , wherein a home position of the number of telescopic members is defined within a region of the chamber below the top surface of the substrate support, each of the number of telescopic members defined to be independently moved upward from the home position so as to enable adjustment of the open volume above the top surface of the substrate support.